Electric reciprocating motor



. (No Model.) 2 Sheets-Sheetl. E. THOMSON.

ELECTRIC REOIPROOATING MOTOR.

.No. 520,810. Patented June 5, 1894.

-(No Model.) 2 Sheets-Sheet 2.

E. THOMSON.-

ELECTRIC REOIPROGATING MOTOR.

No. 520,810. Patented June 5, 1894.

U ITED STATES PATENT ome 5 ELIHU THOMSON, OF SWAMPSOOTT, MASSACHUSETTS,ASSIGNOR TO THE.

TI-IQMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC RECIPROCATING M-OTO R.

SPECIFICATION forming part of Letters Patent No. 520,810, dated June 5,1894.

Application filed July 10, 1 8 91.

To aZZ whom it may concern.-

Be it known that I, ELIHU THOMSON, a citizen of the UnitedStates,.residing at Swampscott, in the county of Essex and State ofMassachusetts, have invented a certain new and useful Improvement inElectric Reciprocating Motors, of which the following is aspecification.

The present invention relates to electric reciprocating mechanism, suchas rock'drilling it is desirable that a powerful reciprocating movementmay be obtained from electric currents. I utilize in my invention acontinuous current for polarizing the apparatus and an alternatingundulatory current for causingthe movable portion of the apparatus tovibrate ata proper rate, the alternating current being caused to haveits periods of alternation to correspond with the natural period ofvibration of the apparatus. The continuous current is made to set up acircular or transverse field of magnetism and alternating currents aresent through a movable coil placed in said field so as to causevibration of said coil.

In the accompanying drawings Figure l is a longitudinal sect on of anelectric reciprocating motor embodying the invention. Fig. 1 shows thedrill to be attached thereto.

7 Figs. 2, 3 and 4 are detail views of the armature; Fig. 5,' sectionthrough the plungerrotating device. of the motor. Fig. 7 is a diagram ofthe operating circuit connections.

The coils O C in Fig. 1 are wound around a central core D D composed ofa hollow iron tube having flanged plates P, P at the ends, and having anouter iron shell H inclosing the coils O, C. These portions form amagnetic circuit around the coils and give rise to an intense magneticfield at the portions F, F, or in the annular space separating the twoiron tubes. The coils O, O, C, C, are wound so that the current movesthrough Fig. 6 shows a simplified form Serial No. 399,043. (No model.)

nections are made by springs or other cur-- rent conveying portions, asat S, S, to proper posts for conveying current to the moving coils. Asinglecoil at T may be used but it is much better to divide the coilinto a number of separate coils carried in a frame and having holdingdevices or bobbins. ,Such

bobbins may be made of German silver .or non-magnetic metal, but Iprefer in many cases to construct them'of wrought iron and 'wind thewire securely in grooves or annular spaces formed therein betweendiaphragms or separators j, 7'. This spool or bobbin is carried upon aspider J, J, in the same manner as an armature would be carried upon itsspider, the spider having arms J, J, constituting webs connecting thebobbins supporting the coil T, and a central hub through which thecentral axis or reciprocating rod R passes, as is clearly shown in Fig.2. When the spool or coil of wire is divided into separate portions, asabove described, the winding and connections must be such as to causethe current to traverse them in the same direction. In other words, theseveral portions must be maguetically'similar so as to form in magneticefiect a single coil. In Fig. 3 the portion which constitutes themovable coil or reciprocating armature of the apparatus is shownseparately in section. It is desirable that its electrical continuity bebroken or cut by slots running transversely to its periphery, as seen inFig. 4 at L L. It is in fact desirable that the iron masses such as theshell H, H, and the core D, D, be properly slit in a directiontransverse to their circumference, or transverse to a line parallel tothe winding on the bobbin T, T. This is for the purpose of preventingthe circulation of induced currents during the reciprocations of thispart of the magnetic field. It is preferred to have the portion J, J, orthe hub of the same sleeved upon. a central rod n, n, andheld. be-

tween buffers or very stifi springs of a slight range ofcompressibility, as at a, a, thestructare being held, in place betweenscrew collars K, K, fixedor sustained by the central axis or rod it. Atthe upper part of the rod R rotating the rod,.

shown more in detail in Fig. 5, these devices consisting or a spiralareprovided devices for up stroke of the rod so as to diminish the upwardblowand accelerate the downward stroke.

Fig, 6 shows a simplified construction, where on] y a single coil (3 isused to magnetiae the central core D, which is continued to form areturn magnetic cirenit such as an outer shell H. in the polar ormagnetic space between these two portions of iron is placed the coil Tcarried ll, centering on the drill tor reciprocation.

axis it, which carries the in raj strongly energized transverse magneticfield, causes vigorous motion or tendency to motion back and forth inthe polar space or transverse magneticfield. In like manner;

the action of the devices shown in Figs. 1,2, 3 and 4 is dependent uponthe passage of an alternating current of slow period through the movablecoil or the bobbin orc'arrier '1, while immersed in a transversemagneti-e 'field'ot great strength provided by the continuous currentwhich passes in the coils 6,0, 4 There results a vibration orlongitudinal oscillation in synchronism with the alterr mating currentspassing, it being necessary to adapt the period ticn oi the moving ifthe alternations are-much too fast the ap ity for the actual work of theapparatus, but

also to suddenly and quickly reverse the metion so that the movementdoes not lag nor get behind the period of the impulses of current, Thespring then is an accelerator of the phase, as it may be termed, Thesprings S also serve to increase the rate of vibration.

The field of magnetism in the annular air space is called a transversefield because its lines are in planes transverse to the core axis. slheconstruction tion, for rebound, spect practically, in the removal 0t i0,nsasses, and this would be in many cases a simplified and preferableconstruction.

The dia, Fig. 7, shows one of the means which may be em loyed foroperating the ap- The by the proper supports J'G Current of analtermating character passing in the coil T while 3 to the natural rateof vizbraparts of the apparatuaas I us will not keep upwith them. Thefunction of the spring Z is not only to take up the blows which arestruck in the upward direction, and which are therefore of no util- IFig. 6 if elaborated and provided with the various-appliances iforrota-i the, vr-ould'differ in no refrom that in Fig. 1, except one setof energizing coils for example, and the accompanying iron para-tus in amagnetic field suitably provided, and rings a", r, are shown as attachedto' opposite points of the winding with brushes resting on these ringsfor the conveyance of alternatin g impulses to the alternating coil ormovable coil of the apparatus, '1, while connections from the brushes19,1), on the commutator are carried to the energizing or continuouscurrent coil 0, "0 stood that the machine M with the rings and with thecommutator winding will apply to any bi-polar construction of armature,and that current may be fed from the line to said machine and drive itas "a motor, the attachments being then made from the exterior source tothe brushes b, will by its rotation generate alternating currents anddeliver them to the rings 1', r, and the coil T, while continuouscurrents will pass to the coils C G. Orthe machines if dynamo in likemanner and so feed the coils, its speed in each case being kept at arate such as will provide the proper rate of alternatingimpulses to thecoil T. It therefore becomes a slow speed machine. more the partrepresented by the letter M may be a winding with its attachmentsexisting on a motor transformer or motor dynamo in which a separatewinding fed by current of different potential causes rotation of themachine, and the winding represented by M furnishes current to thereciprocating apparatus.

While in the description above, the magnetic field has been shown asannularand the magnetic lines radial or transverse to the axis ofapparatus it is evident that the shape of the central core ifrectangular or polygonal instead of round would require a similar shapedcoil and bobbin to fi-t the space. Also it .will be evident that whilethe field isspread uniformly around the axis in the circular space,owing to the part H surrounding the central core on all sides, myinvention would be present were the part H to only partially surroundthe core, or be carried up at two sides only for example, in which casethe magnetic transverse field would not be evenly distributed around theaxis, but would be densest opposite the portions of the shell Hprovided.

As before stated, my invention consists in l the combination with amagnet having such course assumed that the armature, revolves b, inwhich case it Commutator segments lit will readily be underdriven bypower will generate currents as a.

too

, Furtherinfluence of an alternating current travcrsin g the coil.

What I claim as new, and desire to secure by Letters Patent, is

1. The combination of the relatively movable coils or magnets, one ofwhich is supplied with continuous currents, and the other with unbrokenundulatory alternating currents of a definiterate of alternation, tocause vibration of-one of the coils or magnets, the movable coil withits attached parts having a definite inherent rate of vibrationcorresponding with therate of alternation of the propelling current. I

' 2. The combination of the relatively movable coils or magnets,oneofwhich issupplied with continuous currents and the other with unbrokenundulatory alternatingcurrents of a definite rate of alternation, tocause vibration of one of the coils or magnets, the movable coil withits attached parts having resilient devices engaging therewith, andhaving a definite rate of vibration under the influence of thealternating current and the resilient devices, substantiallycorresponding to the rate of alternation of the current.

3. The combination of the continuously energized magnet having outer andinner pole portions, forming between them a transverse field, a coilmovable in said field between such pole pieces and traversed by analternating undulatory current.

4. The combination of the continuously energized magnet, having outerand inner pole portions, forming between them a surrounding ortransverse field and air space, and a coil movably and closely fitted insaid space and traversed by an unbroken undnlatory alternating current,substantially as described.

5. The combination of the magnet having inner and outer pole pieces, thereciprocating rod within the inner pole piece, arms attached to saidreciprocating rod, and extending into the polar space between the polepieces, and a coil carried by said arms and movable in said polar space.

6. The combination of the magnet having inner and outer pole pieces, thereciprocating rod within the inner pole piece, arms attached to saidreciprocating rod, and extending through the inner pole pieceinto thefield space between the pole pieces, and a coil carried by said arms andmovable in said field space.

7. A reciprocating magnet for vibrating electro-motors having a bobbinor support with separators or diaphragms, and magnetically similar coilswound between said separators. I

8. The combination'in a reciprocating electric motor, of thereciprocating rod, the armature sleeved thereon,.stops on said rod, andbufiers between said armature and stops.

In witness whereof I have-hereunto set my hand this 7th day of July,1891.

ELIHU' THOMSON.

, Witnesses:

JOHN W. GIBBONEY, JOHN T. BRODERIOK.

